In the Middle Ages, there was a popular Halloween activity-making "candy for the soul", and children had to go door to door to ask for this cake, which was very similar to the modern trick-or-treating activity.
Every time the children get a piece of this candy, they should pray for the deceased relatives and friends of the candy giver. These prayers will help their relatives and friends find their way from purgatory to heaven. Children will also sing a song "Bread of the Mind", which is similar to the modern "trick or treat, trick or treat, give me something delicious".
Extended data:
There is evidence that in the primitive Celtic tradition, there is indeed a similar "trick or treat" activity. Historians say that Celts will March outside the town dressed as ghosts to drive away ghosts.
Celts believe in the existence of elves and other naughty creatures, and the concept of Halloween pranks may have originated from their rumored activities on Savin Festival. It is reasonable to infer that the Celtic New Year's Eve is similar to the New Year's Eve in the west now-it is a time for people to get rid of shackles and get drunk. The tradition of practical jokes may be derived from this carnival spirit.